VoIP PBX or IP PBX (Internet Protocol Private Branch Exchange) is a telephony system that makes use of IP data networks to facilitate telecommunication. The immediate advantage of VoIP PBX is that enterprises using it need not have to replace their existing phones or phone numbers to accommodate the new VoIP facility. It is a robust technology that works in tandem with the existing communication infrastructures. In other words, the VoIP technology can use the existing PSTN lines via the VoIP gateway, and there is no much of additional infrastructure involved in its entire installation.
How does a VoIP PBX work?
The basic architecture of an IP PBX system consists of an IP PBX server, one or more SIP phones or VoIP phones, and a VoIP gateway, as mentioned already, to connect to the existing PSTN lines (optional though). The IP PBX server functions quite similar to a proxy server. The SIP or VoIP phones, which can be either hardware phones or soft phones, has to register with the IP PBX server, and when they wish to make a call to another phone
Lee Smith writes about VoIP PBX Telephone Systems
VoIP PBX
Hi just wrote about company which saved $20K per month by switching to VoIp so benefits cannot be ignored.